Where Should a King Sit? A 700-Year-Old Chair Will Do.

LONDON — There is a piece of furniture so famous and so important to British history that it sits in its own chapel at Westminster Abbey, behind an iron gate so that onlookers may gawk at it but never touch it.

The item, the Coronation Chair, was commissioned by King Edward I of England to accommodate the Stone of Scone, which was captured from the Scots in 1296. The chair was constructed in the early 1300s, and the stone sits directly under its seat.

The Abbey says that the chair is the oldest piece of furniture in Europe still being used for its original purpose, and that 26 monarchs have been crowned on it since the coronation of Edward II in 1308. Although scholars have questioned whether the chair’s original purpose was to be used in coronations, they agree that it has been a centerpiece of such ceremonies for centuries.

Last month, the Abbey announced that the chair, which was last used during Queen Elizabeth II’s coronation in 1953, would undergo conservation work ahead of King Charles III’s coronation on Saturday. The chair last underwent a restoration from 2010 to 2012.

According to the Abbey, the conservation work will concentrate on cleaning the surface of the chair, which is made of oak and stands at 6 feet 9 inches. Sponges and cotton swabs will be used to remove dirt and stabilize the remaining layers of gilding on both the chair and its base, which was built in the early 18th century.

Krista Blessley, Westminster Abbey’s paintings conservator, is responsible for the restoration of the chair, which is also called St. Edward’s Chair. While the Abbey declined to offer an interview with Ms. Blessley, citing her need to focus on her work, last fall she told Channel 5, a British broadcasting company, that the chair was “very fragile” and that its gilded layers were prone to flaking. Its seat is also covered in graffiti from visitors and Westminster students in the 18th and 19th centuries, she said.

In an interview this spring with The Royal Family Channel, Ms. Blessley said the chair originally had gilded glasswork and would have appeared to be metallic. The chair is also decorated with punchwork — tiny dots used to makes patterns and images — of birds, saints, kings and foliage.

The Stone of Scone, sometimes called the Stone of Destiny, weighs 336 pounds. Over the years, it has been the subject of intense rivalry between Scotland and England. It was stolen by Scottish nationalists on Christmas Day 1950 but recovered months later. The stone was returned to Edinburgh Castle in Scotland in 1996 and will be brought down to London for the coronation.

“It’s actually not a very remarkable looking thing,” David Torrance, a monarchy specialist at the House of Commons Library, said of the stone. “It is, at the end of the day, a sort of crudely cut rectangle of sandstone” that has been damaged and pinned back together, he said.

Because the chair has not been used in decades, it has deteriorated to some degree, Mr. Torrance said. He added that the restoration should ensure that the chair can accommodate both the weight of the stone and the weight of the king, neither of which are regularly in the chair.

The restoration costs have not been disclosed, but Mr. Torrance said he expected the conservation efforts continued until a few days before this weekend’s ceremony.

The other objects in the ceremony, including an orb and a scepter that will be held by King Charles, “symbolize power and authority in a monarchy,” said Anna Whitelock, a professor of the history of monarchy at City, University of London.

Charles will be crowned with the St. Edward’s Crown, which was removed from the Tower of London last year to allow for modifications to it, according to the official website of the British royal family. The king will also wear the Imperial State Crown during the ceremony.

Queen Camilla, who will also be crowned during the ceremony, will have a less grand seat, Professor Whitelock said.

“It won’t be the Coronation Chair, but she will be sitting next to Charles,” she said. “She’s not the main event, but she will be there, both symbolically and sort of in every other sense, in a supporting role.”

While the Coronation Chair has been a fixture in coronations for centuries, it may not always be that way. Professor Whitelock said it was not integral to the ceremony. “Much of the monarchy’s popularity — in some sense, legitimacy today — has been based on the fact that it is this age-old institution,” she said. “It’s always been done like this.” Future monarchs could make changes as they please.

“I think many people see things like the Coronation Chair and the history around it, being the thing that makes the coronation, and indeed the British monarchy, so special,” Professor Whitelock said. “If you start to strip those things out, you wonder what’s left and, indeed, whether what’s left justifies some of the other issues with having an unelected head of state.”